Certain water filter assemblies include a manifold and a filter cartridge. The manifold directs unfiltered water into the filter cartridge and filtered water out of the filter cartridge. The filter cartridge includes a filter medium, such as an activated carbon block, a pleated polymer sheet, a spun cord material, or a melt blown material. The filter medium is positioned within the filter cartridge and filters water passing therethrough.
Over time, the filter medium will lose effectiveness. For example, pores of the filter medium can become clogged or the filter medium can become saturated with contaminants. To insure that the filtering medium has not exceeded its filtering capacity, the filtering medium is preferably replaced or serviced at regular intervals regardless of its current performance. To permit replacement or servicing of the filter medium or the filter cartridge, the filter cartridge is generally removably mounted to the manifold.
Water leaks can form or develop at an interface or connection between the filter cartridge and the manifold, such as where the filter cartridge mounts to the manifold. As an example, such leaks can develop if the water filter assembly is installed incorrectly or is exposed to relatively high water pressures or freezing conditions. Such leaks can negatively affect operation of the water filter assembly and/or the refrigerator appliance and can cause damage if not prevented. Such leaks can also be difficult to detect. In particular, water filter assemblies are often positioned in relatively remote locations within refrigerator appliances such that visually monitoring the water filter assemblies for leaks can be difficult or infrequent. Similar problems can make detecting liquid water and water leaks difficult in other circumstances and locations as well.
Accordingly, a system or method for detecting liquid, such as liquid water, would be useful. In particular, a system or method for detecting liquid water with features for limiting or preventing unnecessarily triggers under damp conditions would be useful.